Baseline dental examinations were conducted in October 1972, on approximately 2200 children (grades 1-12). All participants in grades K-6 chew daily in school under supervision an acidulated phosphate-fluoride (APF) tablet containing 1 mg. F, and swish and swallow the resulting solution. Once a week in school the same children also swish 10 milliliters of 0.2 percent sodium fluoride solution for 60 seconds and then empty contents of the mouth into a cup. A fluoride-containing dentifrice and toothbrushes are distributed to the same children for use at home. These combined preventive procedures will continue in the elementary schools for a minimum of ten years. Follow-up dental examinations are carried out biennially. Final examinations will be made in the fall of 1982 when all senior high school students will have participated continuously in the elementary school program since entering first grade. Children in the 7th and 8th grades of Nelson County's junior high school began to participate in the program in the fall of 1978 and 1979 respectively. High school grades will be brought into the program on an incremental basis in future years.